Josef Mengele’s Selections and Human Experiments at Auschwitz

Josef Mengele’s selections and human experiments at Auschwitz were not separate from one another: both made prisoners subject to his power to classify, exploit, and kill. In 1944, he helped direct deported Hungarian Jews toward forced labor or immediate death, while experiments on twins and dwarves treated prisoners as research material. The postwar testimony of Miklós Nyiszli, a Jewish doctor forced to work for Mengele, and survivors’ accounts decades later reveal the human consequences behind Mengele’s later claims that he had served medicine and saved lives.

Selection and the power to decide

During the summer and autumn of 1944, trains carrying Hungarian Jews arrived at Auschwitz in large numbers. Nyiszli, who had been forced to work as a doctor among the Sonderkommando prisoners, described Mengele spending long periods at the selection platform. His gesture directed people one way; the result was the separation of those assigned to labor from those sent to be killed. Nyiszli’s account presents this not as an incidental task but as a repeated exercise of authority. He attributed the dispatch of hundreds of thousands of Jews to Mengele’s decisions and described the doctor as regarding that work as a patriotic duty.

Mengele also arranged the removal of all three barracks of Hungarian Jewish prisoners when scarlet fever broke out. The people were taken to the crematorium. The episode shows how the camp’s medical authority could be used to determine the fate of an entire group: an epidemic did not lead to care or protection, but to an order ending their lives. Together, selection and this response to disease reveal a system in which medical judgment served persecution and killing.

Experiments and the research system

In the experimental barracks of the camp’s Roma sector, Mengele ordered medical tests on twins and dwarves. Nyiszli’s testimony describes a range of procedures imposed on living prisoners, including blood tests, spinal procedures, and transfusions between twins. They were painful and exhausting, and the prisoners had no choice about participating. Mengele’s research also required that twins under study die together, after which their bodies could be examined. The experiment therefore made the prisoners’ deaths part of its design rather than an unintended consequence.

The research extended beyond the camp. After prisoners were killed, organs were sent to the Institute for Anthropology, Human Heredity and Eugenics in Dahlem, Berlin, directed by Otmar von Verschuer. Packages were marked for urgent handling as war material. This link between Mengele’s work at Auschwitz and an academic institution demonstrates that the experiments were not merely private acts of curiosity: specimens and research were connected to a wider scientific network. Nyiszli also recalled Mengele returning to the dissection room after selections and continuing his investigations in the final months of 1944, even as Germany was losing the war. His attention to the organization of research dossiers stood in stark contrast to the human beings reduced to entries in them.

Testimony against Mengele’s defense

When Rolf later asked his father what he had done at Auschwitz, Mengele described his actions as military duty in the service of German science. He presented selection as the sorting of prisoners according to their capacity for work, claimed that this had saved lives, and argued that twins had benefited from the research. He defended the camp’s killings through a biological vocabulary that cast victims as threats or inferior beings. He also invoked obedience and responsibility to the Nazi state, portraying himself as one part of a larger system rather than an accountable decision-maker.

That defense is contradicted by the evidence of his direct role: he made selections, ordered experiments, and determined that prisoners would be killed for comparative research. Nyiszli’s testimony records both the procedures and Mengele’s repeated presence in the laboratory. The difference is fundamental. Mengele recast deliberate decisions as impersonal necessity; the evidence instead shows a physician exercising authority over people who could neither consent nor refuse, and whose lives he treated as subordinate to his research and ideology.

Survivors’ testimony and later accountability

On the fortieth anniversary of the liberation of Auschwitz, survivors who had been twins, dwarves, or otherwise subjected to Mengele’s experiments called publicly for his capture. Their appeal insisted that he was alive and should face justice. A mock trial at Yad Vashem in Jerusalem brought survivors’ testimony before an international audience over three days. Witnesses described experiments on twins and the coercive treatment of mothers and newborns. Their accounts extended the record beyond Nyiszli’s earlier testimony, establishing the lasting human consequences of practices that Mengele had presented as scientific work.

The testimony helped renew pressure to find Mengele. The United States attorney general called for a review of the case, and the Simon Wiesenthal Center pressed for action. A declassified American memorandum incorrectly suggested that the United States had held Mengele in 1947, provoking public questions about how he had evaded capture. The Office of Special Investigations coordinated a renewed inquiry, while Israeli, American, and West German authorities resumed efforts to locate him. The renewed hunt did not itself amount to a criminal trial, but it carried the survivors’ demand into international public and legal debate.

Degrees, reputation, and the limits of postwar justice

In early 1964, Mengele learned that the universities of Frankfurt and Munich had withdrawn his doctoral degrees in medicine and anthropology. The decision cited his violation of the Hippocratic oath and murders at Auschwitz. He was devastated by the loss of qualifications he had regarded as a source of pride, and burned the letter informing him of it. The revocation challenged the academic standing he had used to frame his conduct as research, even as he continued to regard himself as a servant of German science.

The later public record places his credentials beside the forced experiments, killings, and survivor testimony they could not excuse. The recognition of his victims’ experiences and the withdrawal of his degrees marked forms of accountability, but neither substituted for his arrest and trial. The history of the selections and experiments thus turns on a persistent conflict: Mengele’s attempt to describe organized violence as medicine, against testimony and evidence showing how medical authority was used to deny prisoners both protection and personhood.